As usual, there’s bumper-to-bumper traffic on the streets of Davos, as the global elite are shuttled around in luxury limos or in ‘green’ shuttle-buses.

There’s also a strong security presence -- I saw about a dozen soldiers, some armed, as I scuttled along the icy pavements to the Congress Centre. There’s the usual high security on the entrances to WEF too (airport-style scanners, no liquids allowed).

Davos’s main street, the Promenade, has been invaded by corporations - they’ve paid massive sums to turn tourist shops or cafes into their base for the week.

Introduction: Trump vs Thunberg

Good morning from Davos, where the 50th World Economic Forum is getting underway.

Around 3,000 heads of state, business chiefs, academics, activists, celebrities and journalists have descended for their annual splurge of meetings, speeches, parties, top-level discussions and general pontificating.

And today could be dominated by two extremely different individuals, who are both changing the world in their own way.

In one corner, US president Donald Trump. He’ll give the first keynote speech this morning - a chance to tub-thump his America First agenda, trumpet his (limited) trade deal with China, and hail the ongoing US economic expansion.

The Americans are in town in force. Trump has brought a large delegation, including Treasury secretary Stephen Mnuchin and White House advisor Larry Kudlow.

But across the congress centre, climate activist Greta Thunberg will also be in the spotlight. She’s demanding that governments and corporations wake up to the climate emergency, and take decisive action before our futures are ruined.

As Thunberg and allies wrote in the Guardian last week:

We demand that at this year’s forum, participants from all companies, banks, institutions and governments immediately halt all investments in fossil fuel exploration and extraction, immediately end all fossil fuel subsidies and immediately and completely divest from fossil fuels.

We don’t want these things done by 2050, 2030 or even 2021, we want this done now – as in right now.

Greta Thunberg: At Davos we will tell world leaders to abandon the fossil fuel economy